Switch for arc-lamp circuits.



PATENTED DEC. 13

R. H. HENDERSON.

SWITGH FOR ARC LAMP CIRCUITS.

-APPLIGATIOH FILED MAR. 20, 1903.

NO MODEL.

* WW/ZW WI ZIMSSES' I f7 I mw/zza/ 7 I I I A UNITED STATES Patented December 13, 1904.

PATENT OFFICE.

WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY,

CORPORATION OF PENNSYLVANIA.

SWITCH FOR ARC-LAMP CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 777,631, dated December 13, 1904.

Application filed March 20,1903. Serial No. 148,675. (No model.) i

To all wlwnt it may concern:

Be it known that I, ROBERT I-I. HENDER- soN, a citizen of the United States, and a resident of Newark, county of Essex, State of New Jersey, have invented certain new and useful Improvements in Switches for Arc- Lamp Circuits, of which the following is a specification.

In the use of arc-lamps upon alternatingcurrent circuits difficulty has been found in securing a proper switch for throwing in a lamp or a series of lamps owing to the fact that particularly with lamps of the shunt type there is a strong tendency for arcs to be formed at the terminals of the usual short circuit when the switch is manipulated to break the short circuit and throw in a lamp or a series of lamps. Especially when it happens that the moment of rupture at the terminals of the short circuit is synchronous with the moment when the current is at the peak of a wave this tendency is Very marked, and it is found that dangerous arcs are likely to be formed which may destroy the switch-contacts and involve danger to the operator of the switch.

It is a part of the present invention to provide means whereby the arcs which are formed under the circumstances described shall be rendered innocuous by reason of the fact that provision is made for suppressing the arcs before the damage which they might otherwise create is caused. This function is fully per formed by the switch which is described and shown in the present application for Letters Patent, as will appear from the specification and drawing forming the substance of the application.

The drawing illustrates an elevation of a switch designed to carry out the present invention, together with a diagram of an electric circuit containing a number of shunt arclamps.

While I have mentioned the shunt type of arc-lamp as one in which the difl iculties men-' tioned particularly exist, yet the invention is applicable to any type of arc-lamp and will be found useful in any alternating-current arclamp system.

In connection with the switch about to be described I may make use of a spark-gap or lightning-arrester adapted to take care of lightning discharges in the main circuit, the spark-gap or lightning-arrester being made an element of the switch apparatus and forming a structural part of the apparatus as embodied in practice. It will be understood that this feature may, however, be dispensed with, as it forms no necessary part of the switch apparatus as such.

Referring to the drawing, the frame of the switch is shown at 1, and it is provided with several lugs or extensions 2 2 2 2, by means of which it may be attached to any suitable support, whether to the pole or the pole-base. It will be understood that the device may be attached to the suspension-wire immediately above the lamp or to any other suitable sup port, in which case the particular means of connection may be varied to suit the conditions.

On the rear wall of the frame or casing I support a number of cylinders 3 3 3 3, prefer ably of porcelain or some other good insulating and heat-resisting material. These cylinders I combine in pairs at opposite sides of the frame or casing, and the members of each pair are arranged to cooperate with a reciprocating plunger 4. connected through suitable insulating-bushings 5 5 5 5 with a crosspiece 6, of metal. Within the cylinders, but insulated from the frame or casing, are split cylinders 7 7 7 7, which the appropriate ends of the plungers 4: at enter and with which the said plungers make good electrical contact. The said split cylinders are severally connected to binding-posts 8, 9, 10, and 11, secured to the ends of the cylinders 3 3 3 3. The binding-posts 8 and 9 are connected by a strip of metal 12, as shown. The cylinders 3 3 3 3 are provided with blow-out openings 4:0 &0 a0 10, as shown.

The line-wires 13 14 are connected, through suitable insulating bushings 15 16, to the plungers I 4:, the means ofv connection being suitable binding-clips 17 17 and binding-nuts 18 18. The wires leading to the lamp or series of lamps appear at 19 and 20, and in the present instance they are shown as being connected with a number of shunt-lamps 21 21, although they may be connected with a single lamp of any type or a series of lamps other than shunt-lamps. The wires 19 and 20 are respectively connected to the binding-posts 10 and 11, as shown.

1V hen the apparatus is in the position illustrated, the lamps 21 are cut out, the circuit passing from the line-wire 13 through the clip 17, plunger 4, switch-cylinder 7, binding-post 8, metallic conductor 12, binding-post 9, split cylinder 7, plunger 4, clip 17, and out at the wire 14 at .the other side of the frame or casing. The position of the parts as illustrated can, however, be reversed, so as to bring the opposite ends of the plungers '4 into contact with the split cylinders appropriate to the said ends, and this can be accomplished by means of a screw-bolt 22, secured to the crosspiece 6 and ending in a ring 23, through the medium of which force can be applied to the moving parts of the switch apparatus for reversing the switch, as described. \Vhen such reversal takes place, contact is made between the lower ends of the plungers 4 t and the corresponding cylinders 7 7 before contact is broken at the opposite ends of the plungers. The current from the line now has a path not only through the course above described, but also through the conductor 19, the lamps 21, and the conductor 20. In other words, the reversal of the switch throws in the lamps on the local circuit. hen the operation is continued until a complete reversal takes place that is to say, until the upper ends of the plungers st 4 are completely separated from the cylinders corresponding thereto-the local circuit will be the only natural path for the current except in so far as the tendency already mentioned exists toward the formation of arcs at the points of rupture of the cut-out circuit. While it is true that such arcs may be formed there, yet, owing to the fact that each arc is formed within a small chamber, wherein the tendency of the arc to expand is neutralized and where the supply of oxygen to support the arc is very small, the arcs are immediately extinguished and the current is diverted through the local lamp-circuit without injury to the apparatus or danger to the manipulator of the switch.

By referring to the drawings it will be seen that I place between the plungers Q 1 in such a position as to partially bridge the lamp-circuit two strips 24 and 25 of some suitable metal, preferably a non-arcing metal, the said strips being brought near each other at their ends, so as to leave an air-gap or spark-gap between them. The edges of these strips may be serrated in the form usually given to lightning-arresters, although it is not thought necessary to illustrate this particular feature of the device. Should the line be affected by a lightning discharge or other abnormally high current, it will discharge itself across the airgap without injury to the local apparatus.

The switch structure as a whole will be provided with a suitable cover, (not shown,) which cover will be cut away in line with the curve shown at 30, so as to permit access at all times to the loop or ring, whereby the switch can be reversed.

It will be understood that the details of the described invention may be widely varied without departing from the invention. the essential features of which are set forth in the claim which follows.

The plungers L enter the cylinders loosely, but with very little play, so that they nearly [ill the space within the cylinders when they are pressed into firm contact with the split cylinders therein. Manifestly the openings 40 L0 10 in the cylinders 3 3 3 3 need not be round openings; but I prefer that they should have this shape.

I claim as my invention The combination with a main supply-circuit carrying alternatingcurrents, and a local consumption-circuit, of a switch for cutting the local circuit out and in, the terminals of the said switch being inclosed in small chambers arranged in pairs, the members of each pair being axially in line with each other, contactpieces adapted to make contact at opposite ends with the switch terminals, means for reversing the positions of the contact-pieces, and a protecting device for the switch consisting of an air-gap between the main wires leading to and from the switch.

Signed at New York, in the county of New York and State of New York, this 18th day of March, A. D. 1903.

ROBERT H. HENDERSON.

Witnesses:

WM. H. CArEL, GEORGE H. S'rooxnnrnsn. 

